Casing for arc-lamps.



G. M. LITTLE.

CASING FOR ARC LAMPS.

urmommn FILED Mn 6, 1907.

Patented July 19,1910.

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G. M. LITTLE.

CASING FOR ARG LAMPS. APPLICATION FILED MAY 42, 1907.

964,666. Patented July 19,1910. .7

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UNITED PATENT QFFIGE.

GEORGE M. LITTLE, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO W'ESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

CASING FOR ARC-LAMPS.

T 0 all whom it may concern:

Be it known that I, GEORGE M. LITTLE, a citizen of the United States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Casings for Arc-Lamps, of which the following is a specification.

My invention relates to are lamps, and

particularly to means for ventilating the same.

The object of my invention is to provide especially effective means whereby drafts may always be directed outwardly from the top of the lamp.

IV hen certain kinds of electrodes, such, for instance, as those containing the magnetic mid of iron and the oXids of titanium and chromium, are used in arc lamps, it is necessary to provide means for removing from the interiors of the lamps the vapors and fumes that are given off at the arc in order to prevent the same from condensing and depositing upon the operating parts, or upon other parts in such a manner as to obscure more or less of the light given by the lamps. The means usually employed comprises a chimney the lower end of which opens to the exterior near or at the top of the lamp. It is evidently essential that drafts be always directed outwardly through this chimney and that drafts be prevented from blowing down the chimney, and to this end the structure constituting the subjectmatter of the present application has been provided.

My invention is illustrated in the accompanying drawings, Figure l of which is a view, in elevation, of a lamp constructed in accordance therewith, ome of the parts being broken away for the sake of clearness of illustration. Fig. 2 is a plan view of the top casting of the lamp shown in Fig. 1, a portion thereof being broken away, and Fig. 3 is a sectional view of a portion of the lamp embodying a modification of the structure shown in Fig. 1.

An arc lamp casing 1 is provided with a top or cap 2 comprising two plane and parallel plates 3 and a that are spaced apart and secured together attheir edges by a plurality of vanes 5, the edges of the plates being in exact vertical alinement and the inner edges thereof being square or only very slightly rounded. The lower plate 3 is pro- Specification of Letters Patent.

Application filed May 6, 1907.

Patented July 19, 1910.

Serial No. 372,181.

vided, upon its upper face, with a cylindrical flange 6 that surrounds an aperture through which a chimney tube 7 projects, the upper end of the tube being flush with the upper face of the flange 6. The chimney tube 7 extends downwardly through the lamp, its lower end portion being enlarged and flared and its open end being just above where the arc occurs between the electrodes. The upper plate a is provided, upon its lower face, with an annular boss or ring 10 of somewhat larger diameter than the flange 6, this ring being for the purpose of assist ing in preventing downward drafts. The top 2 is provided with a flange 8 that extends downwardly over the upper end of the casing 1 and between which and a plurality of lugs 9 the casing is secured, the outer cylindrical face of the flange being in vertical alinement with the edges of the plates 3 and a. The plates 8 and l are also connected by cylindrical sleeves 11 through which the leads to the lamp project, terminals 12 being provided upon the exterior of the lamp.

In order to effectually prevent downwardly-directed drafts in the chimney when the wind blows between the plates of the top, it is highly desirable that the upper end of the chimney tube project above the plate at, as shown, and also that the opposing faces of the plates 3 and a be substantially parallel. The vanes 5 are provided for the purpose of breaking the force of heavy winds that may blow upon the lamp so as to reduce the amount of air that may circulate through the top, but may be omitted, if desired, as shown in Fig. 3. The plates 3 and 4c are made of the same diameter and their edges are placed in vertical alinement in order that upward or downward drafts may not be directed into the top, and to this end, the edges of the plates are also made square or are only slightly rounded. I have found that, by the observance of the principles herein outlined, the drafts will always be directed outwardly from the top of the casing, and downward drafts will be effectually prevented.

I claim as my invention:

1. The combination with a casing, of a top therefor comprising two spaced parallel plates of the same diameter the edges of which are joined by vanes, and a chimney tube that projects through and above the lower plate.

2. The combination with a casing, of a top therefor comprising two spaced parallel plates of the same diameter the edges of which are joined by vanes, and a cyllndrical flange of the same outer diameter as said plates extending downwardly from the lower plate, and a chimney tube that projects through and above the lower plate.

8. The combination with a casing, of a top therefor comprising two spaced parallel plates of the same diameter, a chimney tube that projects through and above the lower plate, and an annular flange on the lower face of the upper plate.

4. The combination with a casing, of a top therefor comprising two spaced parallel plates of the same diameter, a chimney tube that projectsthrough and above the lower plate, and an annular flange of greater diameter than the chimney tube on the lower face of the upper plate.

5. The combination with a casing, of a top therefor comprising two spaced parallel plates of the same diameter, and vanes joining the edges of the plates, a chimney tube that projects through and above the lower plate, and an annular flange of greater diameter than the chimney tube on the lower face of the upper plate.

In testimony whereof, I have hereunto subscribed my name this 30th day of April,

GEORGE M. LITTLE. Witnesses:

OTTO S. SOHAIRER, BIRNEY HINES. 

